Abstract: A wearable device worn by a user includes a base, an antenna structure, a ground plane, and a metal element. The base substantially has a hollow structure. The antenna structure is disposed on the base. The ground plane is disposed inside the base. The metal element is adjacent to the ground plane. The ground plane is positioned between the antenna structure and the metal element.

Abstract: A mobile device includes a nonconductive mechanism element and an antenna structure. The antenna structure is formed over the nonconductive mechanism element. The antenna structure includes a feeding connection element, a first radiation element, a second radiation element, a grounding connection element, and a third radiation element. The feeding connection element is coupled to a feeding point. A first end of the first radiation element is coupled to the feeding connection element, and a second end of the first radiation element is open. A first end of the second radiation element is coupled to the feeding connection element, and a second end of the second radiation element is open. The grounding connection element is coupled to a grounding point. A first end of the third radiation element is coupled to the grounding connection element, and a second end of the third radiation element is open.

Abstract: A mobile device includes an antenna element, a first sensing metal element, a second sensing metal element, and a metal connection line. The antenna structure can cover an operation frequency band. The metal connection line is connected between the first sensing metal element and the second sensing metal element. The metal connection line has a resonant frequency which is not within the operation frequency band of the antenna element.

Abstract: A mobile device includes a speaker element and an antenna element. The speaker element includes a conductive portion and a nonconductive portion. The nonconductive portion has a first surface and a second surface which are opposite to each other. The antenna element is adjacent to the nonconductive portion. The antenna element includes a signal source, a first radiation element, and a second radiation element. The signal source is coupled to a feeding point. The first radiation element is coupled to the feeding point. The first radiation element extends from the first surface onto the second surface. The second radiation element is coupled to the feeding point. The second radiation element is disposed on the second surface. The second radiation element is separate from the first radiation element. A coupling gap is formed between the first radiation element and the second radiation element.

Abstract: A wearable device includes a nonconductive base, a metal loop, and a matching circuit. The nonconductive base substantially has a hollow structure. The metal loop is disposed on the nonconductive base, and has a feeding point and a grounding point. The metal loop has at least one notch. The grounding point of the metal loop is coupled through the matching circuit to a ground voltage. An antenna structure of the wearable device is formed by the metal loop and the matching circuit.

Abstract: A multiband switchable antenna structure includes a feeding element, a first radiation element, a second radiation element, circuit branches, and a switch circuit. A first end of the feeding element is a feeding point. A first end of the first radiation element is coupled to a second end of the feeding element. A second end of the first radiation element is open. A first end of the second radiation element is coupled to the second end of the feeding element. The circuit branches have different impedance values. The switch circuit selects one of the circuit branches as a matching branch according to a control signal. A second end of the second radiation element is coupled through the matching branch to a ground voltage.

Abstract: A wearable device includes a nonconductive base, a metal loop, and a matching circuit. The nonconductive base substantially has a hollow structure. The metal loop is disposed on the nonconductive base, and has a feeding point and a grounding point. The metal loop has at least one notch. The grounding point of the metal loop is coupled through the matching circuit to a ground voltage. An antenna structure of the wearable device is formed by the metal loop and the matching circuit.

Abstract: A communication device includes a radiation element, an RF (Radio Frequency) choke element, a DC (Direct Current) block element, an SAR (Specific Absorption Rate) sensor, a transceiver, and a platform. The radiation element has the functions of an antenna and a sensing pad. The radiation element is configured to receive a low-frequency signal and an RF signal. The RF choke element is configured to remove the RF signal. The DC block element is configured to remove the low-frequency signal. The radiation element is coupled through the RF choke element to the SAR sensor. The radiation element is further coupled through the DC block element to the transceiver. The platform is coupled to the SAR sensor and the transceiver.

Abstract: A wearable device includes a nonconductive base, a metal loop, a metal connection element, and a matching circuit. The nonconductive base substantially has a hollow structure. The metal loop is disposed on the nonconductive base. The metal loop has a feeding point. The metal loop is coupled through the metal connection element and the matching circuit to a ground voltage. The antenna structure of the wearable device is formed by the metal loop, the metal connection element, and the matching circuit.

Abstract: A multiband switchable antenna structure includes a feeding element, a first radiation element, a second radiation element, circuit branches, and a switch circuit. A first end of the feeding element is a feeding point. A first end of the first radiation element is coupled to a second end of the feeding element. A second end of the first radiation element is open. A first end of the second radiation element is coupled to the second end of the feeding element. The circuit branches have different impedance values. The switch circuit selects one of the circuit branches as a matching branch according to a control signal. A second end of the second radiation element is coupled through the matching branch to a ground voltage.

Abstract: A handheld electronic device comprises a housing, a receiver, a balance antenna and a body. The housing comprises a top end and a bottom end. The receiver is located in the housing and near the top end, and the balance antenna is located in the housing and near the bottom end. The body is located in the housing and electrically couples to the receiver and the balance antenna.

Abstract: A handheld electronic device comprises a housing, a receiver, a balance antenna and a body. The housing comprises a top end and a bottom end. The receiver is located in the housing and near the top end, and the balance antenna is located in the housing and near the bottom end. The body is located in the housing and electrically couples to the receiver and the balance antenna.